面试一些简单的编程题目

//在有序数组中找出某个数字的位置
#include<stdio.h>
int binarySearch(int a[] , int length,int object)
{
    int head=0,mid=0;
    int tail = length -1;
    while(head<tail)
    {
           mid = (head+tail)/2;
           if ( a[mid] > object)
               tail = mid -1;
           else if(a[mid]<object)
               head = mid +1;
           else
               return mid;
    }
    return -1;
}

int main()
{
    int array[] ={ 1,2,3 ,4 ,5, 6,7,8,9,10};
    int result=binarySearch(array,sizeof(array),6);
    printf("%d",result);
    return 0;
}



//找出有序数组中出现某数字的次数
#include<stdio.h>
int count =0;
void  binarySearch(int a[] , int head,int tail,int object)
{
    if(head<=tail)
    {
        int mid = (head+tail)/2;
        if (a[mid] == object)
        {
            count++;
            binarySearch(a,head,mid-1,object);
            binarySearch(a,mid+1,tail,object);
        }
        else if( a[mid] < object)
        {
            binarySearch(a,mid+1,tail,object);
        }
        else
        {
            binarySearch(a,head, mid-1,object);
        }
    }
}

int main()
{
    int array[] ={ 1,2,2 ,2 ,2, 2,2,2,9,10};
    binarySearch(array,0,sizeof(array)/4-1,2);
    printf("%d",count);
    return 0;
}


//求数组中最大子数组和
#include <stdio.h>
int MaxSum(int a[] ,int length)
{
    int nStart = 0,nSum=0,i;
    for(i=0; i < length; i++)
    {
        nStart = ( nStart+a[i] ) > a[i]? ( nStart+a[i] ) : a[i];
        nSum = nStart>nSum? nStart:nSum;
    }
    return nSum;
}

int main()
{
    int array[]={ 7,-9,8,7,-5,9,10,-20,9,-30,20,49,-50,-60};
    int sum= MaxSum(array,sizeof(array)/4);
    printf("%d",sum);
}


//求最长公共子序列

#include <stdio.h>
int MaxLength(char a[], char b[],int **c,int **back,int m,int n)
{
    int i,j;
    for (i=0;i<m;i++)
        for(j=0;j<n;j++)
            back[i][j] = 0;
    for (i=0;i<m;i++) c[i][0] = 0;
    for (j=0;j<n;j++) c[0][j] = 0;
    for (i=1; i<m;i++)
        for (j=1;j<n;j++)
        {
            if ( a[i]==b[j] ) 
            {
                c[i][j] = c[i-1][j-1] +1;
                back[i][j] = 1;
            }
            else if( c[i-1][j] >= c[i][j-1] )
            {
                c[i][j] =c[i-1][j];
                back[i][j] =2;
            }
            else
            {
                c[i][j] = c[i][j-1];
                back[i][j] = 3;
            }
        }
  return c[m -1][n -1];
}

void LCS(int i,int j, char *a, int **back)
{
    if(i ==0 || j==0) 
        return;
    if (back[i][j] == 1) 
    {
        LCS(i-1,j-1,a,back);
        printf("%c",a[i]);
    }
    else if(back[i][j] == 2)
    {
        LCS(i-1,j,a,back);
    }
    else
    {
        LCS(i,j-1,a,back);
    }
}

int main()
{
    char A[]="ACDWDYEZYXZXXABDYBZZ";
    char B[] ="BYBZACDZYAXXXYZZ";                                                                                                                                                               
    int **C  = new int*[sizeof(A)];
    for (int i=0;i<sizeof(A);i++)
        C[i] = new int[sizeof(B)];
    int **Back = new int*[sizeof(A)];
    for(int i=0;i<sizeof(A);i++)
        Back[i] =new int[sizeof(B)];
    int length = MaxLength(A,B,C,Back,sizeof(A),sizeof(B));
    printf("Max Common Length:  %d\n",length);
    printf("Common String:  ");
    LCS(sizeof(A)-1,sizeof(B)-1,A,Back);
    printf("\nLength Array\n");
    for(int i=0;i<sizeof(A);i++)
    {
        for(int j=0;j<sizeof(B);j++)
            printf("%d  ",C[i][j]);
        printf("\n");
    }
    printf("TraceBack Array\n");
    for(int i=0;i<sizeof(A);i++)
    {
        for(int j=0;j<sizeof(B);j++)
            printf("%d  ",Back[i][j]);
        printf("\n");
    }
}


//约瑟夫环

#include<stdio.h>
#include <stdlib.h>

typedef struct Node
{
    int num;
    struct Node *next;
}LinkList;

LinkList *create(int n)
{
    LinkList *p,*q,*head;
    p = (struct Node*)malloc(sizeof(Node));
    p->num=1;
    head =p;
    q = p;
    for(int i=2;i<=n;i++)
    {
        p= (struct Node*)malloc(sizeof(Node));
        p->num =i;
        q->next =p;
        q=p;
    }
    p->next = head;
    return head;
}

void Jonse(LinkList *&head,int m)
{
    LinkList *p,*q,*s;
    p=head;

    while(p->next != p)
    {
        for(int i=1;i<m;i++)
        {
            q=p;
            p=p->next;
        }
        printf("%d  ",p->num);
        s=p;
        q->next=p->next;
        p = p->next;
        free(s);
    }
    printf("%3d",p->num);
}

void main()
{
    LinkList *head;
    int m,n;
    printf("Enter the number of List: ");
    scanf("%d",&m);
    printf("\nEnter the internal of List: ");
    scanf("%d",&n);
    head = create(n);
    Jonse(head,m);
}



//链表的倒置
#include <stdio.h>
#include <stdlib.h>

typedef struct Node
{
    int num;
    struct Node *next;
}LinkList;

LinkList *create(int n)
{
    LinkList *p,*q,*head;
    p = (struct Node*)malloc(sizeof(Node));
    p->num=1;
    head =p;
    q = p;
    for(int i=2;i<=n;i++)
    {
        p = (struct Node*)malloc(sizeof(Node));
        p->num = i;
        q->next =p;
        q = p;
    }
    p->next = NULL;
    return head;
}

void reverse(LinkList  *&head)
{
    LinkList *p,*q;
    p = head->next;
    q  = p ->next;
    head->next = NULL;
    while( q != NULL)
    {
        p->next = head;
        head =p;
        p =q;
        q = q->next;
    }
    p->next =head;
    head =p;
}

void List(LinkList *head)
{
    while(head != NULL)
    {
        printf("%3d",head->num);
        head = head->next;
    }
}

void main()
{
    LinkList *head;
    int n;
    printf("Enter the length of the List: ");
    scanf("%d",&n);
    head = create(n);
    printf("Before reverse : ");
    List(head);
    reverse(head);
    printf("\nAfter reverse: ");
    List(head);
}

//指针，字符串的理解

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void main()
{
    char *s =(char*)malloc(12);               //这里需要为字符串指针申请内存空间
    const char *sas= "we are the world\0";
    printf("The length of string: %d\n",strlen(sas));
    char *dd[] = { "we","are" ,"the","world","to be better","innocence","somebody","yesterday is history, tomorrow is mystery,but today is gift"};
    char cc[10][10]={"we","are" ,"the","world","be better","innocence","somebody","yesterday"};
    char (*CC)[10] =cc;                 //数组指针出场
    printf("数组指针隆重出场: %s  %s\n", CC,CC[0],CC[1]);
    scanf("%s",s);
    printf("%s",s);
    printf("\n%s",sas);
    for(int i=0;i<sizeof(dd)/4;i++)   //指针数组，可以用sizeof求出数组的长度，指针的字节是4，所以需要除以4
    {
        printf("\n%s",dd[i]);
        if(i==7)
        {
            printf("\n");
            for(int j=0; j<20; j++)   //这里不能使用sizeof(dd[7])，来获取长度，这里只能获取指针的长度
                printf("%c",dd[i][j]);
        }
    }

    for(int i=0; i<sizeof(cc);i++)
    {
        for(int j=0; j<sizeof(cc[10]);j++)
            printf("%c",cc[i][j]);
        printf("\n");
    }
}

//字符串的快速排序

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int Partition(char **quicksort,int left,int right)
{
    char *random = quicksort[left];
    int l = left,  r = right+1;
    while (true)
    {
        while( (strcmp(quicksort[++l] , random)<0 ) && l<r) ;
        while( strcmp(quicksort[--r],random) > 0 )  ;
        if( l >= r) 
            break;
        char temp[20]={};
        strcpy(temp,quicksort[l]);
        strcpy(quicksort[l],quicksort[r]);
        strcpy(quicksort[r],quicksort[l]);
    }
    strcpy(quicksort[left],quicksort[r]);
    strcpy(quicksort[r],random);
    return r;
}

void QuickSort(char **quicksort ,int left,int right)
{
    if(left < right)
    {
        int part = Partition(quicksort,left,right);
        QuickSort(quicksort,left, part-1);
        QuickSort(quicksort,part+1,right);
    }
}

void main()
{
    char *quicksort[ ] = {"me","he","who","she","what","new"};
    QuickSort(quicksort, 0,sizeof(quicksort)/4-1);
    for(int i=0;i<sizeof(quicksort)/4; i++)
        printf("%s  ",quicksort[i]);
}



//快速排序

#include <stdio.h>
#include <stdlib.h>
int  Partition(int *sort,int left,int right)
{
    int x=sort[left];
    int l=left, r=right+1;
    while(true)
    {
        while( sort[++l] < x && l < r) ;
        while( sort[--r] > x  ) ;
        if( l >=r)
            break;
        int temp = sort[l];
        sort[l] = sort[r];
        sort[r] = temp;
    }
    sort[left] = sort[r];
    sort[r]   = x;
    return r;
}

void QuickSort(int *sort,int left,int right)
{
    if(left<right)
    {
        int part = Partition(sort,left,right);
        QuickSort(sort,left,part-1);
        QuickSort(sort,part+1,right);
    }
}
void main()
{
    int sort[] = {8,3,9,31,32,32,32,33,78,7,10,11,12};
    QuickSort(sort, 0,sizeof(sort)/4-1);
    for(int i=0;i<sizeof(sort)/4; i++)
        printf("%d  ",sort[i]);
}



#include <iostream>
using namespace std;
typedef struct Node
{
    int num;
    struct Node *next;
}LinkList;

typedef struct LinkQueue
{
    LinkList *head, *tail;
}queue;

void insert(queue *Q, int m)
{
    LinkList *p;
    p = (Node*)malloc(sizeof(Node));
    p->num = m;
    p->next  = NULL;

    if(Q->tail == NULL)
    {
        Q->tail = p;
        Q->head =p;
    }
    else
    {
        Q->tail->next =p;
        Q->tail =p;
    }
}

void del(queue *Q)
{
    LinkList *p; int x;

    if( Q->head == NULL)
    {
        cout<<"The Queue is Empty"<<endl;
    }
    else
    {
        x = Q->head->num;
        cout<<x <<endl;
        p = Q->head;
        if (Q->head == Q->tail)
        {
            Q->head = NULL;
            Q->tail    = NULL;
        }
        else
        {
            Q->head = Q->head->next;
        }
        free(p);
    }
}

void main()
{
    queue  *Q =(LinkQueue*)malloc(sizeof(LinkQueue));
    Q->head = NULL;
    Q->tail    = NULL;
    for(int i = 0 ; i <=10; i++)
        insert(Q,i);
    for(int i= 0; i <= 10; i++)
        del(Q);
}

// 用链表实现的栈

#include <iostream>
#include <stdio.h>
#include <array>
#include <vector>
#include <list>
#include <map>
#include <hash_map>
#include <queue>
using namespace std;

typedef struct Node{
    int num;
    struct Node *next;
}LinkList;

typedef struct Stack{
    LinkList *bottom, *top;
}stack;

void push(stack *S, int num)
{
    LinkList *p;
    p = (Node *)malloc(sizeof(Node));
    p->num =num;
    if(S->bottom == NULL)
    {
        S->bottom =p;
        S->top  =p;
        p->next = NULL;
    }
    else
    {
        p->next = S->top;
        S->top  = p;
    }
}

int pop(stack *S)
{
    LinkList *p; int x;
    if(S->bottom == NULL)
    {
        cout<< "The Stack is Empty"<<endl;
    }
    else
    {
        x = S->top->num;
        cout<< x<<" ";
        p = S->top;
        if( S->top == S->bottom)
        {
            S->top = NULL;
            S->bottom =NULL;
        }
        else
        {
            S->top = S->top->next;
        }
        free(p);
    }
    return x;
}

void main()
{
    stack *S = (Stack *)malloc(sizeof(Stack));
    S->bottom = NULL; S->top = NULL;
    for(int i=0;i<=10;i++)
        push(S,i);
    for(int i=0;i<=10;i++)
        pop(S);
}


//使用栈实现四则运算

#include<iostream>
#include <stack>
using namespace std;
void main()
{
    stack<int> s_num;
    stack<char> s_oper;
    char *express =new char[100];
    cout<<"Enter the expression:"<<endl;
    cin>>express;
    int sum=0, number1,number2;
    int  len = strlen(express);
    for(int i=0;i < len; i++)
    {
        if(express[i] >= '0' && express[i] <='9')
            sum = sum*10+(express[i] - '0');
        else
        {
            if(express[i] ==' ')
                continue;
            s_num.push(sum);
            sum=0;
            if(express[i] =='=')
            {
                while(!s_oper.empty())
                {
                    number1 = s_num.top();
                    s_num.pop();
                    number2 = s_num.top();
                    s_num.pop();
                    switch(s_oper.top())
                    {
                    case '+':
                        s_num.push(number2+number1);
                        break;
                    case '-':
                        s_num.push(number2-number1);
                        break;
                    case '*':
                        s_num.push(number2*number1);
                        break;
                    case '/':
                        s_num.push(number2/number1);
                        break;
                    default:
                        break;
                    }
                s_oper.pop();
                }
            }

            if(!s_oper.empty())
            {
                if(s_oper.top() =='*' ||  s_oper.top() == '/')
                {
                    number1 = s_num.top();
                    s_num.pop();
                    number2 = s_num.top();
                    s_num.pop();
                    if(s_oper.top() =='*')
                        s_num.push(number2*number1);
                    else
                        s_num.push(number2/number1);
                    s_oper.pop();
                }
            }

            switch(express[i])
            {
                case '+':
                    if(s_oper.empty())
                        s_oper.push('+');
                    else
                    {
                        number1 = s_num.top();
                        s_num.pop();
                        number2 = s_num.top();
                        s_num.pop();
                        if(s_oper.top() == '+')
                            s_num.push(number2+number1);
                        else
                            s_num.push(number2-number1);
                        s_oper.pop();
                        s_oper.push('+');
                    }
                    break;
                case '-':
                    if(s_oper.empty())
                        s_oper.push('-');
                    else
                    {
                        number1 = s_num.top();
                        s_num.pop();
                        number2 = s_num.top();
                        s_num.pop();
                        if(s_oper.top() == '+')
                            s_num.push(number2+number1);
                        else
                            s_num.push(number2-number1);
                        s_oper.pop();
                        s_oper.push('-');
                    }
                    break;
                case '*':
                    s_oper.push('*');
                    break;
                case '/':
                    s_oper.push('/');
                    break;
                default:
                    break;
            }
        }
    }
    cout<<"Sum is : "<< s_num.top()<<endl;
}



//两个栈实现队列的功能
#include <iostream>
#include <stack>
using namespace std;
template <class T>
struct Queue
{
    void push(T &t)
    {
        s1.push(t);
    }

    T front()
    {
        if(s2.empty())
        {
            if(s1.size() == 0) throw;
            while(!s1.empty())
            {
                s2.push(s1.top());
                s1.pop();
            }
        }
        return s2.top();
    }


    void pop()
    {
        if(s2.empty())
        {
            while(!s1.empty())
            {
                s2.push(s1.top());
                s1.pop();
            }
        }
        if(!s2.empty())
            s2.pop();
    }

    stack<T> s1;
    stack<T> s2;
};

int main()
{
    Queue<int> Q;
    int i;
    for ( i=0; i<10; ++i)
        Q.push(i);
    for(i=0;i<10;++i)
    {
        cout<< Q.front()<<endl;
        Q.pop();
    }
    return 0;
}

//整数转换为字符串 itoa函数
#include <iostream>
using namespace std;
void main()
{
    int m,i=0;
    char temp[10], str[10];
    cin>> m;
    while(m != 0)
    {
        temp[i++] = m%10+'0';
        m = m/10;
    }
    temp[i] ='\0';
    str[i] ='\0';
    int j=0;
    while(temp[j] != '\0')
    {
        str[--i] = temp[j++];
    }
    for(i=0;i<=j;i++)
        cout<<str[i];
}

//字符串转换为整数 atoi函数
#include <iostream>
using namespace std;
void main()
{
    char *str=new char[10];
    cin>>str;
    int num=0;
    int len = strlen(str);
    for(int i=0;i<len;i++)
        num = num*10 + (str[i] -'0');
    cout<<num;
}

//字符串复制

#include <iostream>
#include <stdio.h>
#include <assert.h>
using namespace std;

char * strcpy(char *dest, const char *source)
{
    assert((dest != NULL )&&(source != NULL));
    char *address = dest;
    while( *source != '\0')
        *dest++ = *source++;
    *dest ='\0';
    return address;
}

void main()
{
    char *source = "We are the World";
    char *dest = new char[20];
    char *address=strcpy(dest,source);
    cout<<address<<endl;
}


//循环右移字符串n位
#include <iostream>
using namespace std;
void LoopMove(char *str,int steps)
{
    int  n= strlen(str) - steps;
    char temp[100]; 
    strcpy(temp, str+n);
    strcpy(temp+steps,str);
    *(temp+strlen(str))  = '\0';
    strcpy(str,temp);
}


void LoopMove(char *str,int steps)
{
    int n = strlen(str) - steps;
    char temp[100];
    memcpy(temp,str+n,steps);
    memcpy(temp+steps,str,n);
    memcpy(str,temp,n+steps);
}

void main()
{
    char str[30];                         //char *str = "I live in Guangzhou",str[i] ='m'; 默认指针指向常量，不可修改
    int i;
    for(i=0;i<9;i++)
        str[i] =i+'0';
    str[i]='\0';
    LoopMove(str,4);
    cout<<str<<endl;
}

//map结构记录字母或单词出现的次数, 还没实现根据value来排序。

#include <iostream>
#include <map>
#include <string.h>
using namespace std;

void main()
{
    map<char,int> m ;
    map<char,int>::iterator m_iter;
    char *str = "Yesterday is history,tomorrow is mystery,but today is gift";
    while(*str != '\0')
    {
        if(m[*str] >= 1)
            m[*str]++;
        else
            m[*str] = 1;
        str++;
    }
    for(m_iter = m.begin(); m_iter !=m.end(); m_iter++)
        cout<<m_iter->first <<" :" <<m_iter->second <<" ";


    map<string,int> word_map;
    map<string,int>::iterator word_iter;
    string bb[10]={"Yesterday","is","history","tomorrow","is","mystery","but","today", "is","gift"};
    for (int i=0;i<10;i++)
    {
        if(word_map[bb[i] ] >=1)
            word_map[ bb[i] ] ++;
        else
            word_map[bb[i]] = 1;
    }
    for(word_iter = word_map.begin(); word_iter !=word_map.end(); word_iter++)
        cout << word_iter->first.c_str() <<" :" <<word_iter->second <<" ";
}


//qsort函数字符串的快速排序

#include <iostream>
using namespace std;

int comp( const void *A, const void *B)
{
    return strcmp((char*)A, (char*)B);
}

int comp_num(const void *A, const void *B)
{
    if(*((int*)A) >= *((int*)B) ) return 1;
    else return -1;
}

void main()
{
    const int row= 5;
    const int col = 10;
    char a[row][col] = { "hzhida", "is", "a ","diligent","man"};
    qsort(a,row,sizeof(a[0]),comp);
    for(int i=0;i<row;i++)
        cout<<a[i] <<"\t";

    int A[col] ={100,55,20,30,50,60,70,90,67,10};
    qsort(A,sizeof(A)/sizeof(int),sizeof(int),comp_num);
    for(int i=0;i<col;i++)
        cout<<A[i] <<"\t";
}


//String 类

#include <iostream> 
using namespace std;
class String
{
public:
    String(const char* str = NULL);              //普通构造函数
    String(const String &other);                   //拷贝构造函数
    ~String(void);                                         //析构函数
    String & operator =(const String &other); // 赋值函数
    void  print();
private:
    char *m_data;
};

String::String(const char *str )
{
    if (str == NULL)
    {
        m_data = new char[1];
        *m_data = '\0';
    }
    else
    {
        m_data = new char[strlen(str)+1];
        strcpy(m_data, str);
    }
}

String::~String(void)
{
    delete m_data;
}

String::String(const String &other)
{
    m_data = new char[strlen(other.m_data)+1];
    strcpy(m_data, other.m_data);
}

String &String::operator=(const String &other)
{
    if(this == &other)
        return *this;
    delete [] m_data;
    m_data = new char[strlen(other.m_data) +1];
    strcpy(m_data,other.m_data);
    return *this;
}

void String::print()
{
    cout<<m_data<<endl;
}

void main()
{
    const char *m="long ago, in ancient China, the peakcock rule over the goldmen city";
    String M(m);                 //普通构造函数
    M.print();
    String Z(M);                    //拷贝构造函数
    Z.print();
    String Y = M;                //赋值函数
    Y.print();
}


汉诺塔问题
#include <iostream>
using namespace std;
void TowerHanoi(int n,char x, char y, char z)
{
    if(n)
    {
        TowerHanoi(n-1, x, z, y);
        cout<< "Move top disk from: "<< char(x) <<"   to: "<<char(y)<<endl;
        TowerHanoi(n-1, z, y, x);
    }
}

void main()
{
    int n=0;
    cout <<"input the level of tower: ";
    cin>>n;
    TowerHanoi(n, 'A','B','C');
}


#include <iostream>
using namespace std;
void TransferString(const char *pInputStr, long lInputLen,char *pOutputStr)
{
    int i;
    for(i=0; i<lInputLen;i++)
    {
        if( pInputStr[i] > 'A' &&  pInputStr[i] < 'V')
        {
            pOutputStr[i] = pInputStr[i] + (char)37;
        }
        else if(pInputStr[i] >= 'V' && pInputStr[i] <= 'Z')
        {
            pOutputStr[i]  = pInputStr[i] + (char)11;
        }
        else 
            pOutputStr[i]  = pInputStr[i];
    }
    pOutputStr[i] ='\0';
}

void main()
{
    char *aa="Axs3mWss";
    char  *bb = new char[20];
    TransferString(aa,strlen(aa),bb);
    cout<<bb<<endl;
}


#include <iostream>
using namespace std;
void main()
{
    char *aa = new char[100];
    char *bb = new char[100];
    cin>>aa;
    int i;
    for( i=0; i<strlen(aa); i++)
        bb[strlen(aa) - i -1] = aa[i];
    for(i=0; i<strlen(aa); i++)
    {
        if(aa[i] == bb[i])
            continue;
        else
        {
            cout<<"NO"<<endl;
            break;
        }
    }
    if( i == strlen(aa) )
        cout<< "YES"<<endl;
}

#include <iostream>
using namespace std;
void main()
{
    char *aa = new char[100];
    cin>>aa;
    int i;
    for(i=0; i<strlen(aa)/2;i++)
       {
           if(aa[i] == (aa[strlen(aa) -i-1]))
               continue;
           else
           {
               cout<<"NO"<<endl;
               break;
           }
    }
    if( i == strlen(aa)/2)
        cout<<"YES"<<endl;
}